Are you a man who grew up in a house full of girls? While it might seem like you’d have some advantages in dating, what with being familiar with the ways of women and all, new research shows that men who grow up with only sisters are viewed as less sexy by other women.

Researchers at the University of Texas have just published a study in the journal Psychological Science where they detail their findings on the behavior of rats raised in particular groups. The male rats who were raised solely with female rats–their “sisters”–were found to be less sexually active later on than the male rats who were raised with other male rats.

The lack of mating wasn’t due to lack of effort however. Researchers found that female rats were less likely to invite sexual activity from the rats that had been raised with many females.

The study’s author, David Crews, stressed how the study shows the importance of family and that the findings of rat’s behavior can be linked to humans as well. “Families are particularly important in shaping personalities. The environment where you were raised doesn’t determine personality, but it helps to shape it,” he said. (via the Telegraph)